Glucooligosaccharide production by Leuconostoc mesenteroides fermentation with efficient pH control, using a calcium hydroxide-sucrose solution

Abstract

95.3% of the sucrose in a feed batch fermentation (300 g/L) was hydrolyzed by Leuconostoc mesenteroides subp. mesenteroides NRRL B-23188 glucansucrase. Further, the glucose of sucrose formed glucooligosaccharides (GOS) of degree of polymerization (DP) over 2, together with 91.6% of the maltose (200 g/L). Lime saccharate (lime sucrate) was used to control the pH during fermentation. The GOS products had DP between 2 and 7. When Streptococcus mutans mutansucrase (0.1 U/mL) reacted with 0.1% sucrose, addition of 0.1 ~ 10% GOS to the mutansucrase reaction digest resulted in a 56 ~ 90% reduction of mutan formation. GOS also reduced E. coli (72.2%) and Salmonella sp. (over 40.0%) growth, when 2.5% GOS was used as a single carbon source, compared to growth using glucose. The calculated glycemic index and glycemic load of GOS was 8 and 1, respectively, based on a 10 g carbohydrate serving. GOS was calculated to have 2.43 kcal/g. After a glucose tolerance test was performed using C57BL/6 mice, we found that mice treated with GOS showed a 59.4% lower increase in plasma glucose than those treated with maltose.